2, the key is the customer company, you have to rely on the experience of dealing with both sides, if the other company's requirements are not high, it doesn't matter, they should not care. And the other party went to the tax office to check the tickets.
3. If the requirements of the client company are very high (according to the companies I contacted, such as Midea and Gree, they are not allowed to make mistakes), and this kind of mistake is found after their certification and can be returned in the same month, you should void it in the same month (because you know that they have been certified, so you must stamp the invoice without certification) and reopen it in the same month, so you don't need to go to the tax office for approval. It's simple.
If you return the invoice every other month, it will be troublesome. First of all, you can't void the invoice, and the client company will definitely ask you to reissue it. Then you can only make a negative invoice first, and then make a positive invoice. You should know that it is very troublesome to issue negative invoices. You need to go to the tax office and send you a "certificate of return or discount" approved by the local tax authorities. Can they cooperate?
So the most important thing for you is to judge the practice of the client company. This little problem won't affect them. I believe they will recognize it (because they have been certified, there is no certification stamp, and it is also very troublesome to stamp them for tax). Both sides had better communicate well.